Electric pickup



Aug., 26, i930. H. P. DONLE 1,774,494

ELECTRIC PICKUP Filed Novl 5, 1926 mlmyun Y Patented vAug. 26, 1930 UNITED As'lnrrzs PATENT ori-*ica HAROLD P. DONIE, F MERDEN, CONNECTICUT, ASSIGNOB; BY ASEEl'KEi'tTMENTI?S,Y T0 RADIO INVENTIONS, INC., A CORPORATCN 0F NEW YORK ELECTRIC vPICKUP Application mea November 5, 192s. sum1 ne. reacts. l

My invention relates to mechanism for the reproduction of sound and' particularly to a Y device for reproducing sounds recorded on vWax records and the like and transmitting them electrically to a distance and usually am liying them. s

ne object is to provide a ldevice which is simple and'reliable, easily adjusted and capable of faithful reproduction ot sound. Another object is to provide a device of this character which is portable and can be used with various phonographs and the like.

ln its preferred to which is pivoted a jointed arm. This arm is provided 'with an electromagnet having an armature to which is secured the usual jing' an the pick-up rest on the lnner end 8 whenk needle. Vibrations oi the needle as it follows 'tne groove of the record induce a fluctuating current through the magnet coil and hence causes signal currents which may be controlled, amplified 'and reproduced in any Way desired. Y

l* ig. l is a side View and vertical section of a device embodying one form of my invention and showing the magnetic needle carrier in dotl and dash line folded back or lifted to facilitate changing the record and the needle. Fig. 2 is a transverse sectional view on the plane of the line 2-2 ci Fig. l showing particularly how the needle is supported.

Fig. 3 is another sectional view on the plane of line 3--3 showingthe way the magnet case is constructed.

vFig. l is a detail View of one bearing of the armature and needle. Y

Fig. 5 is a plan View on a small scale showing the device 'in use.

The housing 6 is adapted to rest upon any suitable support convenient to the4 turnA table?. .Y

The arm consists ot the inner part 8 pivoted to the housing and the outer part 9 hinged to part 8 and carrying a casing for the magnet and needle carrier above the rec ord ll;

The housing is preferably provided with a Weighted base l2 suciently broad so that the center of gravity of the parts will be Withinthe'perimeter of thebase when the arm is form it consists of a base folded back as shown in th'e dot and dash line position of Fig. 1.

The rheostat 13 is mounted in the housing and may be held in place by its sleeve 14 and nut 15. The adjustable arm of the rheo stat is carried by the shaft 16 controlled by the knob 17, above. The ring 18 forms a bearingfor the arm A8. The spring washer 19 takes up play and prevents chattering. The housing isprovided with an inlet or inlets 2 0 for the to the amplifier and loud speaker.`

Another Wire (not shown) may pass thru hole 2l to the magnet coil. A pin and slot 22 limits the swing of the arm soas to avoid into thewire. The outer end of the arm 9 folded back. The joint 23 should also be packed so as to prevent chattering but allow such free movement as is required to accommodate the needle. A

The needle-operated current modifying means may be in various forms. 1n the one shown, there is an electromagnet consisting of one or more layers 24 of permanent magneti material with pole pieces 25 on which are mounted the coils 26. The armature 27l is preferably resilient and has a needle carrier or holder 28 extending from one end. A convenient connection is the shank part 29 soldered or riveted to the armature 27.

so incomlng Wires for connection Y enY One end of the armature is supported between the sott rubber washers 30 on the rod 3l. The position of this end may be adjusted vby the nuts 32 and 33. The s lit soit rubber tube 34 surrounds the shan 29 of the needle holder and is held The rheostat 13 and the adjusting knob 1"!"4 constitutes a volume regulating means for the amplifier.

The base plate 88 serves to support the mag-- net and needle structures. The screws 37 pass through the spacing tubes 39. The screws 40 and nuts 41 and i2 secure the magnet plates in place. The threaded pillars. 43 support the cover 44 and screws l5 which hold the device to the arm 9.

Altho l have shown a simple term of device it should be understood that the inventionis not limited to the specific disclosure.

l claim l. A. magnetic pick-up comprisin'glmagnet coils, an armature, a needle helder secured thereto, and projecting trom one end thereof, adjustable resilient means for supporting the opposite end of the armature, a stationary clamp and a resilient sleeve supporting the armature in the clamp between the magnet coils and the needle holder. A

2. An electromagnetic pick-up comprising a magnet liaving a coil and poles, an armature at' one side thereof having a needle holder at itslower end, resilient means for supporting the weight of said armature between the magnet and the needle holder, resilient means for supporting the upper end of said armature above said magnet and a single rotatable member for adjusting the spacing between the armature and the magnet, said armature being movable longitudinally and in a plane parallel to the magnet poles.

3. yA magnetic pick-up comprising an electro magnet, an armature therefor, having a needle holder extensin, a yoke having a bearing i'oi said extension with a screw/seat on each side or" the bearing, a resilient busliing on said extension in said bearing, a cap piece and two screws one ineach side of the cap piece for clamping said cap piece to said yoke and compressing said bushing and a resilient support for the opposite end oiv said armature.

4. An electromagnetic pick-up comprising a casing, a permanent magnet having a plurality of poles, windings carried by said poles, a lexiblearinature 'having a plane surface presented to said poles, a needle holder at one end oi said armature, resilient means for supporting said armature with respect to said magnet, said supporting means being located between said needle holder and said plane surface, additional resilient supporting means/ior said armature at the end remote from said needle liolder, and means for adjusting said armature toward all of said poles by a single movement whereby the distance between said poles and said armature may be varied without moving either of said poles.

5. An electromagnetic pick-up comprising a casing, a magnet contained therein and having a pole piece, a coil carried by said pole piece, a movable armature resiliently supported adjacent to said pole piece but withan air gap between said pole piece and said armature, and means for adjusting the position of said armature with respect to said pole piece, said adjustment causing no other change in the magnetic path comprising said support between said needle holder and saidtirst-named support, a magnet comprising a pole piece having a coil mounted thereon, said magnet being located adjacent said armature at a point between said resilient supports, said armature being vibratable vertically and horizontally.

'HARGLD P. DGNLE. 

